A cell search is an important step in a baseband processing process in a long term evolution (Long Term Evolution, LTE for short) technology. In the baseband processing process, cell information is acquired through the cell search. During the cell search, a synchronization position of a cell needs to be detected. For example, primary synchronization detection, a secondary synchronization detection, and the like of the cell are performed.
Take the primary synchronization detection for example. In an LTE system, a base station sends one local sequence at an interval of 5 ms; and a user equipment receives, by using an antenna, the local sequence sent by the base station, filters the local sequence by using a low-pass filter, obtains received data, and inputs the received data into a primary synchronization detection apparatus. The size of the received data is 1.4 M, and the received data contains 9600 sampling points. According to an existing primary synchronization detection method, the primary synchronization detection apparatus obtains the received data and carries out three correlation operations, that is, NID2=0, NID2=1, and NID2=2, on each of all the 9600 sampling points in the received data. NID2 is a type 2 network identity (Network Identity, NID2 for short). Correlation results and position information corresponding to the correlation results are obtained through the foregoing correlation operations. Then, the correlation results are compared with a threshold; sequencing is performed on correlation results greater than the threshold; and finally, a primary synchronization position is determined according to the sequencing, and a number of the primary synchronization position in a group is taken as an NID2 value.
According to an existing primary synchronization detection method and apparatus, three correlation operations are carried out on each of all the 9600 sampling points in the received data, totally 28800 correlation operations need to be carried out, and therefore a large number of calculation resources are required. The primary synchronization detection apparatus needs to use a large number of circuits to complete the foregoing correlation operations. As a result, a cost for implementing the primary synchronization detection apparatus is high, and operating power consumption is high. The same defects also exist in an existing secondary synchronization detection method and apparatus. In conclusion, the cost for implementing the existing method and apparatus for detecting a synchronization position of an LTE cell is high, and the operating power consumption is high.